1. Field of the Invention
This invention relates to the art of protecting the users of exothermic reacting chemical oxygen generators from heat released by the generators and specifically deals with a disposable tin can type chlorate candle oxygen generator with a snap-on cap having mechanism for activating the candle and delivering the oxygen to a cap carried face mask where the body of the can is insulated with a hydrate salt layer sandwiched between refractory fiber insulation layers so that the can can be handled without discomfort from heat released during the oxygen generating decomposition of the chlorate candle.
In my prior U.S. Pat. Nos. 3,702,305 and 3,725,156 there are disclosed and claimed chemical formulations and ignition cone compositions adapted for oxygen generator cells disclosed and claimed in the Churchill and Thompson U.S. Pat. No. 3,736,104. These compositions and generator cells can be used with the present invention to avoid heretofore required oxygen dispensing and cell carrying cases described and claimed in the Churchill, Thompson, and McBride U.S. Pat. No. 3,733,008.
2. Prior Art
The Jackson and Bovard U.S. Pat. No. 2,558,756 seeks to insulate an oxygen generating composition in a canister with an envelope of potassium perchlorate between the composition and canister which is alleged to decompose endothermically with evolution of oxygen under the heat of reaction of the composition in the canister. The patentees contend that such an envelope of potassium perchlorate plus glass wool surrounding the envelope in the canister will hold the external temperature of the canister to a maximum of about 200.degree. C. (392.degree. F.). Such high temperatures do not permit the canister to be grasped by the user and, therefore, Jackson and Bovard were forced to mount the canister in an envelope providing an air space around the canister and formed of a relatively non-heat-conducting material such as a laminated fabric resin equipped with perforations for radiating heat. Since potassium perchlorate has a low heat conductivity and a very low heat of decomposition into the chloride and oxygen, it would appear that these characteristics of the perchlorate are the reason for the insulating action and not, as stated in the patent, by an endothermic decomposition.